减:

var a = new Date(); 警报(“等待几秒钟，然后点击确定”); var b = new Date(); Var差= (b - a) / 1000; console.log("You waiting: " + difference + " seconds");

在bash中:

bc <<< "$(date --date='1 week ago' +%s) - \
    $(date --date='Sun,  29 Feb 2004 16:21:42 -0800' +%s)"

它确实需要安装bc和gnu日期。

我用YYYY和ZZZZ表示整数值，表示年份，MM和NN表示整数值，表示一年中的月份，DD和EE表示整数值，表示一个月中的一天。

var t1 = new Date(YYYY, MM, DD, 0, 0, 0, 0);
var t2 = new Date(ZZZZ, NN, EE, 0, 0, 0, 0);
var dif = t1.getTime() - t2.getTime();

var Seconds_from_T1_to_T2 = dif / 1000;
var Seconds_Between_Dates = Math.abs(Seconds_from_T1_to_T2);

一个便于将来参考的资源是MDN站点

或者，如果你的日期以javascript可以解析的格式出现

var dif = Date.parse(MM + " " + DD + ", " + YYYY) - Date.parse(NN + " " + EE + ", " + ZZZZ);

然后您可以使用该值作为毫秒差(dif在我的两个例子中具有相同的含义)

var a = new Date("2010 jan 10"),
    b = new Date("2010 jan 9");

alert(
    a + "\n" + 
    b + "\n" +
    "Difference: " + ((+a - +b) / 1000)
);

简单的方法:

function diff_hours(dt2, dt1) 
 {

  var diff =(dt2.getTime() - dt1.getTime()) / 1000;
  diff /= (60 * 60);
  return Math.abs(Math.round(diff));

 }


function diff_minutes(dt2, dt1) 
 {

  var diff =(dt2.getTime() - dt1.getTime()) / 1000;
  diff /= (60);
  return Math.abs(Math.round(diff));

 }

function diff_seconds(dt2, dt1) 
 {

  var diff =(dt2.getTime() - dt1.getTime()) / 1000;
  return Math.abs(Math.round(diff));

 }

function diff_miliseconds(dt2, dt1) 
 {

  var diff =(dt2.getTime() - dt1.getTime());
  return Math.abs(Math.round(diff));

 }


dt1 = new Date(2014,10,2);
dt2 = new Date(2014,10,3);
console.log(diff_hours(dt1, dt2));


dt1 = new Date("October 13, 2014 08:11:00");
dt2 = new Date("October 14, 2014 11:13:00");
console.log(diff_hours(dt1, dt2));

console.log(diff_minutes(dt1, dt2));

console.log(diff_seconds(dt1, dt2));

console.log(diff_miliseconds(dt1, dt2));

function parseDate(str) {
  const [dateStr, timeStr] = str.split(' ');
  const [m,d,y] = dateStr.split('/');
  const [h,min] = timeStr.split(':');
  const date = new Date(y,m,d,h,min,0, 0);
  
  return date;
}

const date1 = parseDate('28/6/2022 22:55');
const date2 = parseDate('28/6/2022 22:58');
const diffInSeconds = (date2 - date1) / 1000;

console.log(diffInSeconds)